The best game of all time? Starflight I and II! Any game that remotely resembled it, I've bought, including GalCiv. I've just started playing it and I have hopes. To me what made those games great is the same thing that great literature has: a sense of total immersion in another universe. They created this, despite primitive graphics and animation, by making it impressionistic. That is, your mind filled in the gaps of reality. Again the comparison to literature, I've never seen a science fiction/fanstasy novel turned to cinema that ever approaches the experience of reading it, LOTR for example. The key elements to SF was that it was the perfect mix of resource management, interaction, combat, surprise, and humor. One of the best features was that not everything was explained in the manual and you were allowed to discover. All of this was within a complex plot line, that you were free to discover at leisure. It is the only game that ever completely took me away from this universe. It seems that today the popular first-person shooters have taken over the gaming world and the developers have blinders on pandering to the adrenaline junkies which I sometimes am. Inevitably people will tire of that, and hopefully return to intelligent, even literary creations. There are a good number that feel this way as a team has been trying to develop an SFIII, now with one of the original programmers, but that's been ongoing for years. Incidentally, several of the programmers from SF programmed Star Control.
Well, I'll stop rambling and get back to gaming!